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It was reported that during the positioning of the ceiling suspension, the hanger failed, causing heavy cables to fall from the ceiling.There is no allegation of death or serious injury.However, it is uncertain whether this event is likely to recur and potentially cause serious injury.Based on the available information, this issue has been determined to be a reportable event.Philips has initiated an investigation into this complaint.
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Issue description: philips received a complaint on the digitaldiagnost c50 indicating that the cable hangers fell due to the thread in the carriage section wears out under normal use.The device was in clinical use and there was no patient or user impact.There was no allegation of death or serious injury.Investigation findings: -the field service engineer (fse) attended site and conducted an analysis, confirmed the reported issue that the cable hanger had fallen down.Based on the fse's analysis, during normal operation, as the cs tube is moved around, the central threaded bolt rotates back and forth within the carriage nut.The fse noted that the hose hangers experience wear as the system is moved around on the ceiling suspension.As the hose moves, the threads rotate, and over time, the 'female' casting bracket threads of the hose hanger wear out, causing the hose to fall.Fse installed the hanger, following that, test and verification procedures were carried out, system was returned to full functionlaity.The philips r&d team performed a root cause analysis and identified the following: -the holder¿s nut and screw are intentionally designed without a locking mechanism, permitting free rotation during cs movement.Over time, repeated motion causes thread wear, loosening the screw-nut connection and eventually leading to detachment of the connection rod.However, even if detachment occurs, the cable hose remains securely suspended due to its natural elasticity, stiffness, and three-point fixation.The detached component poses no risk of personnel contact or wire exposure.Design evaluation: material selection: the screw (low-carbon steel) and nut (stainless steel) are known for their high hardness, rigidity, and wear resistance, which benefits in minimizing the probability of threads wore.Additionally, these materials are commonly used for screw and nut.Reliability testing: the cable hose holders are secured to the auxiliary rails of both longitudinal and lateral rail systems.Reliability testing for longitudinal and lateral movements has been successfully completed, with all results meeting specifications.The design fulfills the durability requirement for 10 years of operation.Root cause analysis: during normal operation, as the cs moved, the threaded connection rod rotated back and forth within the cable clamp pulley nut.This repeated movement caused severe wear on the nut threads.Preventive actions: the following preventive actions should be implemented to avoid recurrence of this issue.-according to pm (preventive maintenance) manual, during pm activities, cables and the corrugated hoses checking are required to be performed annually, which can reduce the potential issues that may cause hose holder fall.-in the instruction for use (ifu) it was clearly defined that this product requires proper operation, planned maintenance, and checks the user must perform routinely, which are essential to keep the product operating safely, effectively and reliably.Resolution: fse installed the hanger.Test and verification were performed on the equipment and documented in the test and verification report.Device is returned to full functionality.Final reportability assessment: -the reporting decision was re-evaluated based on the updated risk assessment.The system did not cause or contribute to a death or serious injury.The reported issue does not affect system functionality but presents a negligible risk due to the potential detachment of the hose holder, it would not be likely to cause or contribute to a death or serious injury if this were to recur.Therefore, this issue has been determined not to be a reportable event.
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